Coated welding rod



Patented Aug. 29, 1944 COATED WELDING ROD Walter L. Baker, Covington, Va., assignor to West Virginia. Pulp and Paper Company, New York,

N. Y. a corporation'of Delaware No Drawing. Application March 24, 1943,

Serial No. 480,339

3 Claims.

My present invention relates to ferrous rods for electric welding, and more particularly to coverings therefor. It has long been recognized that the best results are obtained in electric welding whenthe rod is provided with a suitable fluxing material to overcome the efiect of any oxidation of the metal and to prevent contamination Y of the weld, and it has been proposed to coat the road with coating materials of various types. I

have now discovered a combination of flux and protective covering which I have found to give superior results. I

In carrying out my invention I first coat the rod with a preferably hot borax solution which has a' gravity of 30 Baum or heavier, thereby coating the rod with a firm glassy covering of borax pentahydrate. If a more dilute solution is applied, borax decahydrate is formed which has a lower fusion point and forms a layer of less density and usefulness for the purpose. In order to protect the "coating so applied, and further provide for the proper reducing atmosphere during the welding operation, I then apply a covering of paper which has been coated with waterglass, which is sodium .silicate, NazSiOs. For best results I use a'ribbon of'strong unfilled paper which is moderately sized and of about /8ths of an inch in width which previous to application is passed through a coating bath of waterglass of approximately'28 Baum, after which it is, while still wet, wrapped around the rod in an overlapping helix whereby the turns of the ribbon are sealed upon themselves and upon the rod. While other grades of paper may be used, I prefer kraft paper having a moderate amount of sizing therein, 1. e., sized to 6 to 10 seconds by the ammonium thiocyanate-ferric chloride flotation method at 80 F., since it is without mineral filler and has great strength. In this manner .an insulating layer is formed upon the rod which prevents shorting when the body of the rod is unintentionally brought into contact with the work or other surface upon which it would make an electric circuit. The layer thus formed also protects the rod against rough handling; and the fact that the water glass is exterior of the paper due to the moderate amount of sizing therein, renders the surface smooth and hard. The layer of coated cellulosic material is, however, readily oxidizable and has been found to furnish the ation. I

The rod is wrapped from approximately one inch from the top, which allows a space for the electric clamp, to the other end of the rod which isleit bare to insure initial contact with the work. a

In coating the paper ribbon the latter may be drawn through a bath of waterglass of the gravity mentioned, or thereabouts, and applied while wet to the rod in the manner already described. The treatment thus applied to the rod may be had for all types of ferrous welding rods from the softest steel to a steel of extreme hardness.

In use the sodium silicate acts not only asan adhesive but also fireproofs the paper to such extent that while still combustible it will not itself support combustion. The silicate further moistureproofs the rods whereby they can be used in damp places or in inclement weather without allowing the moisture to dissolve the flux or dampen the rods sufilciently to cause spattering. The sodium silicate has the further advantage that it does not chemically combine with borax, thus permitting the latter to function as a flux. It also aifords the proper amount of heat insulation.

While I have described my preferred embodiment in full detail, it is to be understood that variations will occur to those skilled in the art without departing from the spirit of my invention or the scope of the appended claims.

I claim:,

1. A welding rod for ferrous electric welding of. the type having an inner coating of a fluxing substance and an outer covering of paper, the same being characterized by the inner layer consisting of a hard glassy coating of borax pentahydrate.

2. A welding rod for ferrous electric welding of the type having an inner coating of fluxing substance and an outer covering of paper, the same being characterized by the inner layer consisting of a hard glassy coating of borax pentahydrate and by the outer covering consisting of an overlapping helix of strong, sized, paper having no proper reducing conditions for the welding opersubstantial amount of filler therein and coated with waterglass which serves to seal the turns of the helix to one another and to the flux-coated rod.

3. A welding rod for ferrous electric welding according to claim 2, in which the paper is kraft and has both sides thereof coated with waterglass.

WALTER L. BAKER. 

